Version 4.7.1001 works great. After I update to 4.7.1029, all I get is a cursor, it doesn't even get to the login screen. It has taken a couple of hours to figure out what was causing the problem.
My solution was to boot into safe mode, uninstall Avast, reboot, install Avast 4.7.1001(latest from CNet), reboot, get the virus definitions, and don't upgrade.
As soon as I upgrade, same thing, Vista Home Premium won't boot. This Vista build is only a week old on a new machine.
I would now like to see the versions on your web site, as Avast will always show that there is a newer version, and I won't know when it is a working newer version (aka NOT 4.7.1029). I was surprised when I didn't see anybody else complain.